Erwin gave half of his oranges to a friend. He then gave half of what was left to another friend. He again gave half of what was left to a third friend, and so on, up to a fifth friend, after which he was left with only one orange. How many did he have at the start?

Please answer clearly and explain the solution clearly and easy to understand. Thanks!
(guaranteed medal for a good answer)

Question

Erwin gave half of his oranges to a friend. He then gave half of what was left to another friend. He again gave half of what was left to a third friend, and so on, up to a fifth friend, after which he was left with only one orange. How many did he have at the start?

Please answer clearly and explain the solution clearly and easy to understand. Thanks!
(guaranteed medal for a good answer)

anonymous · Answer

32

anonymous · Answer

let he started with a oranges..
after 1st friend he had=a/2
after 2nd a/4
after 3rd a/8

and so..on after fifth a/32
a/32=1
a=32

anonymous · Answer

this is GP series kind of problem....

moongazer · Answer

what is GP series also please explain my other question

anonymous · Answer

http://en.wikipedia.org/wiki/Geometric_progression